Feature: Add Get-GitBranchSlug

src/Generate-DockerImageVariantsHelpers/public/Get-GitBranchSlug.Tests.ps1

@@ -0,0 +1,177 @@
+$here = Split-Path -Parent $MyInvocation.MyCommand.Path
+$sut = (Split-Path -Leaf $MyInvocation.MyCommand.Path) -replace '\.Tests\.', '.'
+. "$here\$sut"
+
+Describe "Get-GitBranchSlug" {
+
+    Context 'Behavior' {
+
+        It 'Errors when commit message does not match convention' {
+            $badCommitMsgs = @(
+                'Blabla: Add files' # Wrong type
+                ' Enhancement: Add files' # Preceding space
+                'Enhancement:  Add files' # Double space between ':' and description
+                'enhancement: Add files' # Wrong casing of type's first letter
+                'Enhancement: add files' # Wrong casing of description's first letter
+                'enhancement : Add files' # Extra space between type and ':'
+                'Enhancement(something): Add files' # No space between type and scope
+                'Enhancement (something):Add files' # No space between ':' and description
+                'Enhancement  (something): Add files' # Extra space between type and scope
+                'Enhancement (something):  Add files' # Extra space between ':' and description
+                'Enhancement ((something): Add files' # Non-word characters in scope
+            )
+            $expectedError = "Check your commit message convention"
+
+            foreach ($msg in $badCommitMsgs) {
+                Get-GitBranchSlug -CommitMessage $msg -ErrorAction Continue -ErrorVariable err 2>$null
+                $err.Exception.Message | Should -Match $expectedError
+
+                {
+                    Get-GitBranchSlug -CommitMessage $msg -ErrorAction Stop
+                } | Should -Throw $expectedError
+            }
+        }
+
+        It 'Gets the desired slug(s) with "/" after the commit message type' {
+            $cases = @(
+                @{
+                    msg = 'Breaking: Add foo'
+                    expectedSlug = 'breaking/add-foo'
+                }
+                @{
+                    msg = 'Breaking (foo): Add foo'
+                    expectedSlug = 'breaking/foo-add-foo'
+                }
+                @{
+                    msg = 'Change: Add foo'
+                    expectedSlug = 'change/add-foo'
+                }
+                @{
+                    msg = 'Change (foo): Add foo'
+                    expectedSlug = 'change/foo-add-foo'
+                }
+                @{
+                    msg = 'Chore: Add foo'
+                    expectedSlug = 'chore/add-foo'
+                }
+                @{
+                    msg = 'Chore (foo): Add foo'
+                    expectedSlug = 'chore/foo-add-foo'
+                }
+                @{
+                    msg = 'Docs: Add foo'
+                    expectedSlug = 'docs/add-foo'
+                }
+                @{
+                    msg = 'Docs (foo): Add foo'
+                    expectedSlug = 'docs/foo-add-foo'
+                }
+                @{
+                    msg = 'Enhancement: Add foo'
+                    expectedSlug = 'enhancement/add-foo'
+                }
+                @{
+                    msg = 'Enhancement (foo): Add foo'
+                    expectedSlug = 'enhancement/foo-add-foo'
+                }
+                @{
+                    msg = 'Feature: Add foo'
+                    expectedSlug = 'feature/add-foo'
+                }
+                @{
+                    msg = 'Feature (foo): Add foo'
+                    expectedSlug = 'feature/foo-add-foo'
+                }
+                @{
+                    msg = 'Fix: Add foo'
+                    expectedSlug = 'fix/add-foo'
+                }
+                @{
+                    msg = 'Fix (foo): Add foo'
+                    expectedSlug = 'fix/foo-add-foo'
+                }
+                @{
+                    msg = 'Hotfix: Add foo'
+                    expectedSlug = 'hotfix/add-foo'
+                }
+                @{
+                    msg = 'Hotfix (foo): Add foo'
+                    expectedSlug = 'hotfix/foo-add-foo'
+                }
+                @{
+                    msg = 'Refactor: Add foo'
+                    expectedSlug = 'refactor/add-foo'
+                }
+                @{
+                    msg = 'Refactor (foo): Add foo'
+                    expectedSlug = 'refactor/foo-add-foo'
+                }
+                @{
+                    msg = 'Style: Add foo'
+                    expectedSlug = 'style/add-foo'
+                }
+                @{
+                    msg = 'Style (foo): Add foo'
+                    expectedSlug = 'style/foo-add-foo'
+                }
+            )
+
+            foreach ($c in $cases) {
+                Get-GitBranchSlug -CommitMessage $c['msg'] | Should -Be $c['expectedSlug']
+                Get-GitBranchSlug $c['msg'] | Should -Be $c['expectedSlug']
+                $c['msg'] | Get-GitBranchSlug | Should -Be $c['expectedSlug']
+            }
+        }
+
+        It 'Lowercase' {
+            $msg = 'Fix: Fix Something'
+            $expectedSlug = 'fix/fix-something'
+
+            Get-GitBranchSlug -CommitMessage $msg | Should -Be $expectedSlug
+        }
+
+        It 'Strip preceding and trailing spaces' {
+            $msg = 'Fix: Fix something   '
+            $expectedSlug = 'fix/fix-something'
+
+            Get-GitBranchSlug -CommitMessage $msg | Should -Be $expectedSlug
+        }
+
+        It "Replace characters which are not words or '.' with '-'" {
+            $msg = 'Fix: Fix some!.@thing'
+            $expectedSlug = 'fix/fix-some-.-thing'
+
+            Get-GitBranchSlug -CommitMessage $msg | Should -Be $expectedSlug
+        }
+
+        It "Replace '*' with 'x'" {
+            $msg = 'Fix: Fix some*thing'
+            $expectedSlug = 'fix/fix-somexthing'
+
+            Get-GitBranchSlug -CommitMessage $msg | Should -Be $expectedSlug
+        }
+
+        It "Replace contiguous '-' with single '-'" {
+            $msg = 'Fix: Fix some---thing'
+            $expectedSlug = 'fix/fix-some-thing'
+
+            Get-GitBranchSlug -CommitMessage $msg | Should -Be $expectedSlug
+        }
+
+        It "Replace first '-' with '/'" {
+            $msg = 'Fix: Fix Something'
+            $expectedSlug = 'fix/fix-something'
+
+            Get-GitBranchSlug -CommitMessage $msg | Should -Be $expectedSlug
+        }
+
+        It "Strip trailing '-'" {
+            $msg = 'Fix: Fix Something---'
+            $expectedSlug = 'fix/fix-something'
+
+            Get-GitBranchSlug -CommitMessage $msg | Should -Be $expectedSlug
+        }
+
+    }
+
+}

src/Generate-DockerImageVariantsHelpers/public/Get-GitBranchSlug.ps1

@@ -0,0 +1,42 @@
+function Get-GitBranchSlug {
+    [CmdletBinding(DefaultParameterSetName='Default',SupportsShouldProcess)]
+    param (
+        [Parameter(Mandatory,ParameterSetName='Default',Position=0)]
+        [ValidateNotNull()]
+        [string]$CommitMessage
+    ,
+        [Parameter(ValueFromPipeline,ParameterSetName='Pipeline')]
+        [object]$InputObject
+    )
+
+    process {
+        try {
+            if ($InputObject) {
+                $CommitMessage = $InputObject
+            }
+
+            $commitMessageConventionRegex = '^(Breaking|Change|Chore|Docs|Enhancement|Feature|Fix|Hotfix|Refactor|Style)(:| \(\w+\):) [A-Z].+'
+            if (!($CommitMessage -cmatch $commitMessageConventionRegex)) {
+                throw "Check your commit message convention. Commit '$CommitMessage' does not match regex: $commitMessageConventionRegex"
+            }
+
+            # Shell one-liner: BRANCH=$( echo "$MSG" | awk '{print tolower($0)}' | sed 's/^\s*\|\s*$//g' | sed 's/[^a-zA-Z0-9.*]/-/g' | sed 's/[*]/x/g' | sed 's/-\+/-/g' | sed 's/-/\//' | sed 's/-$//' )
+            $slug = $CommitMessage.ToLower()  # Lowercase
+            $slug = $slug -replace '^\s*|\s*$', '' # Strip preceding and trailing spaces
+            $slug = $slug -replace '[^a-zA-Z0-9.*]', '-' # Replace characters which are not words or '.' with '-'
+            $slug = $slug -replace '[*]', 'x' # Replace '*' with 'x'
+            $slug = $slug -replace '-+', '-' # Replace contiguous '-' with single '-'
+            $slug = $slug -replace '^(\w+)-', '$1/' # Replace first '-' with '/'
+            $slug = $slug -replace '-$', '' # Strip trailing '-'
+
+            $slug
+        }catch {
+            if ($ErrorActionPreference -eq 'Stop') {
+                throw
+            }
+            if ($ErrorActionPreference -eq 'Continue') {
+                $_ | Write-Error -ErrorAction Continue
+            }
+        }
+    }
+}